The generation of power, and correspondingly, machines which use power to produce work, such as by the turning of a shaft by electric power, are quite important to modern industry and society. Electric power is used to run a large number of machines which vary substantially in output capability, depending upon the task, from less than one horsepower to several thousand horsepower and even greater, to accomplish specific tasks. Electric power is also used to power electric lights and many electric appliances.
The sources of electric power also vary widely, including large electric power generating plants using, for instance, hydroelectric capability, fossil and/or nuclear fuels, among others. Electric power produced by such plants is then supplied to individual users, through large, complex and expensive transmission and distribution systems. Power is lost in the transmission and distribution system. Alternatively, small, stand-alone electric power sources such as electric generators or micro turbines, which are typically run by fossil fuel (gasoline) engines, natural gas turbines or other similar devices, are capable of supplying small amounts of power for specific users. These generators are also not 100% efficient.
Electric motors are also less than 100% efficient, as are systems using electric power directly, such as lighting systems. Some energy is lost in carrying out specific work, i.e. turning a shaft or lighting a filament in a bulb, for instance. Efficiencies of modern electric motors can be quite high, however, exceeding 90%. It is desirable that electric motors or similar devices have efficiencies as high as possible, and further, it is desirable to produce electric power using as little energy as possible. Historically, it has been a goal to actually be able to increase electric power from input to output, although this has not been heretofore realized.
Furthermore, it is highly desirable to have a capacity of local sources of electric power, particularly inexpensive power, independent of existing power distribution systems, without the requirement of large supplies of fuel, such as fossil fuel in particular. One example is for powering irrigation systems in, for instance, third world countries, where the cost of energy to run such systems adds significantly to the cost of food production. Economic electric-powered vehicles are also desirable and are another example where system improvements would be advantageous to the environment.